It can be appreciated that a mattress has been used for years. Typically, a mattress is used to support a human body for rest or during an illness where a person is bedridden.
While these mattresses are suitable for comfort and to support a person during their phase of bed rest, it does not provide support during an upright position of up to 90° or greater. A person would lose contour support if a conventional mattress was used in an upright position of up to 90° or greater, whether in the supine or prone position.